Doppler ultrasound of carotid arteries
Samir Haffar M.D.
Assistant Professor of internal medicine
Doppler US of carotid arteries
Anatomy of carotid arteries
Normal Doppler US of carotid arteries
Causes of carotid artery disease
Effect of extra-carotid diseases
Extracranial cerebral arteries
All arteries that carry blood from heart up to base of skull
Right & left sides of extracranial circulation not symmetrical
Variations in extracranial circulation
Few
• Left CCA & SCA share single trunk
• Left vertebral artery arising directly from aortic arch
• Right vertebral origin arising directly from aortic arch
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
Vertebral artery course
V1
V0
V2
V3
V4
BA
VAs asymetric in 75 % – Left dominant in 80 %
Posteriorly directed loop when exists C1 transverse process
2 VAs units to form basilar artery: collateralization
Doppler US of carotid arteries
Anatomy of carotid arteries
Normal Doppler US of carotid arteries
Causes of carotid artery disease
Effect of extra-carotid diseases
All carotid artery examinations should be
performed with:
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
• Gray-scale US
• Color Doppler
• Power Doppler
• Spectral Doppler
Integrate gray scale, color flow, & spectral findings
Position for scanning the carotid arteries
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
Patient lie down in supine or semisupine position
Head hyperextended & rotated 45° away from side being examined
Higher-frequency linear transducers (≥ 7.5 MHz)
Doppler ultrasound of carotid arteries / Tips
• Begin each scan on same side, usually the right
• Avoid excess pressure on carotid bifurcation to avoid
– Stimulate carotid sinus Bradycardia
Syncope
Ventricular asystole
– Compress arteries to cause spurious high velocities
Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
Intima-Media complex
Normal value ≤ 0.8 mm
Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
Wall of CCA, bulb, or ICA
Best measured on far wall
Only intima & media included
Normal carotid bifurcation
Black & white US
ICA Larger & lateral
ECA Smaller & internal
Normal flow separation
Color Doppler ultrasound
Longitudinal scan to visualize carotid arteries
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
Anterior
Posterior
Lateral
Carotid bifurcation
Longitudinal B-mode image of carotid bifurcation
ICA & ECA seen in same plane
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
Normal flow reversal zone in ICA
Velocities highest near flow divider
Flow reversal on opposite side
to flow divider
Flow reversal zone
Opposite to origin of ECA
Internal & external carotid artery
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
2 small branches originating from ECA
Power Doppler US
Typical normal Doppler spectra
Common carotid artery
Internal carotid artery
External carotid artery
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
PSV: 45 – 125 cm/sec
Difference between 2 sides < 15 cm/sec
Dicrotic notch
Normal feature
Ginat DT et al. Ultrasound Quarterly 2011 ; 27 : 81 – 85.
Closure of aortic valve with temporary cessation of forward flow
Resumption of forward flow by elastic rebound of aortic wall
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Coiling of ICA
Congenital - Bilateral - Symmetrical
Abnormal Doppler flow in tortuous vessel
Tortuous CCA displays color
Doppler eccentric jets of flow
High velocity due to eccentric
jet in tortuous CCA
Tortuosity can increase velocity, although there is no stenosis
Try sampling just beyond the curve
Abropoulos NL et al. Vasc Endovascular Surg 2007 ; 41 : 417 – 427.
Temporal tapping of ECA
“Saw-tooth” appearance
Small regular deflections (TT)
Frequency corresponds to rate of temporal tapping
Deflections best seen during diastole
Temporal tap
Internal & external carotid artery findings
ICA
temporal tap
ECA
temporal tap
Normal + / − +
Significant ICA stenosis − +
Significant ECA stenosis + −
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Not proved reliable
Differentiation between ICA & ECA
Features ICA ECA
Size Usually larger Usually smaller
Temporal tap Usually negative Usually positive
Pulsed Doppler Low resistance High resistance
Orientation Posterior Anterior
Branches Rarely Yes
Protocol for VA examination
– Direction of flow
– Waveform configuration
– Measure PSV
Longitudinal VA between transverse processes
Cauded survey
– Follow artery cauded to its origin
Cephalad survey
– Follow artery cephalad above transverse processes
Ultrasound of normal vertebral vessels
Cephalad flow throughout cardiac cycle
Low resistance flow pattern
VA origin regularly seen by experienced sonographers
Size: variable & asymmetric – Mean diameter 4 mm
PSV: 20 – 40 cm/sec – <10 cm/sec potentially abnormal
Vertebral artery
Vertebral vein
May occasionally be seen adjacent to VA
Flow caudad & nonpulsatile
Normal vertebral artery origin
V0
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Normal vertebral artery & vein
V2
Vertebral artery & vein seen between vertebral processes of spine
Color Doppler Pulsed Doppler
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Subclavian artery
Mirror image below pleura
Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.
Elsevier Churchill Livingstone, London, 2nd edition, 2005.
Color Doppler US Pulsed Doppler US
Normal triphasic waveform
Doppler US of carotid arteries
Anatomy of carotid arteries
Normal Doppler US of carotid arteries
Causes of carotid artery disease
Effect of extra-carotid diseases
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Extracranial carotid artery & stroke
• Stroke is third leading cause of death in USA
• > 500.000 new cases of CVA reported annually
• 20 – 30% of stokes due to severe carotid artery stenosis
• Stenosis involves ICA within 2 cm of bifurcation
• CEA* more benefical than medical tt in symptomatic
or asymptomatic patients with > 70% carotid stenosis**
* CEA: Carotid endarterectomy
** NASCET: North American Symptomatic Carotid Endartectomy Trial
** ECST: European Carotid Surgery Trial
Common sites for extracranial arterial disease
Most common site at carotid bifurcation
with plaque extending into ICA
Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
Plaque characterization
Low Lipid – < SCM – Flow void
Moderate Collagen – Easy to see – > SCM
High with shadow Calcification – Focal or diffuse
Echogenicity
Calcification: no correlation with neurologic symptoms
Focal hypoechoic zones: Hemorrhage – Necrosis – Lipid
Heterogenous plaque
Common sources of cerebral emboli: TIA – Stroke
Poor US results for ulcer detection
Plaque surface features
Appearance of atheromatous plaques
Homogeneous echolucent Homogeneous echogenic
Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
Heterogeneous plaque Cauliflower’ calcification
Calcified plaque
Calcific plaque with shadow
obscuring portion of the bulb
Interrogate artery beyond plaque
Shadowing segment < 1 cm
No turbulent flow: unsignificant stenosis
Damped or turbulent flow: tight stenosis
Shadowing segment > 2 cm
Degree of stenosis indeterminate
Other modalities recommended
Sources of error in ulcer diagnosis
Plaque surface irregular
but not ulcerated
Adjacent plaque
simulate ulceration
Image plan does not include
the ulcer
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Large plaque ulcer
Power Doppler
“eddy flow”
Color Doppler
Pseudo-dissection
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Ulcerated plaque or twinkle artifact
Scale 86 cm/sec, color in diastole
Color flow disappeared
Color artifact continues to twinkle
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Hard plaque in proximal ICA
Questionable flow at plaque surface
Relationship between diameter reduction
& cross-sectional area reduction
Diameter reduction
(%)
Cross-sectional area reduction
(%)
30 50
50 75
70 90
Cardinal Doppler parameter to grade stenosis
Best documented Doppler parameter for carotid stenosis
Peak Systolic Velocity (PSV)
Quite valuable for detecting high-grade carotid stenosis
End Diastolic Velocity (EDV)
Avoid errors of collateralization
Avoid errors of physiological factors:
BP – Pulse rate – Cardiac output – Peripheral resistance
PSV ratio
Relationship of flow, velocity & lumen size
Spencer MP & Reid JM. Stroke 1979 ; 10 : 326 – 330.
Grading stenosis – PSV ratio
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Proximal: 2 cm proximal to carotid bulb
At stenosis: same Doppler angle if possible
Normal value < 2.0
Grant EG et al. Radiology 2003 ; 229 : 340 – 346.
17 authors:
1 Moderator
16 panelists
San Francisco, Calif
October 22–23, 2002
PSV, EDV & PSV ratio & degree of ICA stenosis
NASCET criteria
Grant EG et al. Radiology 2000 ; 214 : 247 – 252.
PSV & EDV ICA /CCA PSV
ICA stenosis on angiogram
ECST 2 (1998)
European Carotid Surgery Trial
(C – A / C) x 100
NASCET 1 (1991 – 1998)
North American Symptomatic Carotid Endartectomy Trial
(B – A / B) x 100
1 NASCET. N Engl J Med 1991 ; 325 : 445 – 453.
ICA stenosis on angiogram
Diameter reduction
* NASCET: North American Symptomatic Carotid Endartectomy Trial
** ECST: European Carotid Surgery Trial
30% 65%
40% 70%
50% 75%
60% 80%
70% 85%
80% 91%
90% 97%
* NASCET
(B – A / B) x 100
** ECST
(C – A / C) x 100
Degree of ICA Stenosis in Doppler US*
Consensus Criteria – NASCET criteria
ICA stenosis ICA PSV ICA EDV PSV ratio
(%) cm/sec cm/sec ICA/CCA
Normal < 125 < 40 < 2.0
< 50% < 125 < 40 < 2.0
50 – 69% 125 – 230 40 – 100 2.0 – 4.0
> 70% > 230 > 100 > 4.0
Near occlusion variable variable variable
Total occlusion undetectable undetectable not applicable
* Diameter reduction
Grant EG et al. Radiology 2003 ; 229 : 340 – 346.
Degree of ICA Stenosis in Doppler US*
Consensus Criteria – NASCET criteria
ICA stenosis ICA PSV ICA EDV PSV ratio
(%) cm/sec cm/sec ICA/CCA
Normal < 125 < 40 < 2.0
< 50% < 125 < 40 < 2.0
50 – 69% 125 – 230 40 – 100 2.0 – 4.0
> 70% > 230 > 100 > 4.0
Near occlusion variable variable variable
Total occlusion undetectable undetectable not applicable
* Diameter reduction
Grant EG et al. Radiology 2003 ; 229 : 340 – 346.
Aliasing or high velocity jet
Area of highest velocity in area of stenosis
Adjustment of color gain
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Color gain at 80%
Marked turbulence of ICA & ECA
No luminal narrowing
Anatomy of bifurcation
demonstrated more accurately
Color gain at 66%
Color Doppler bruit
Extensive soft tissue color Doppler bruit surrounds
carotid bifurcation with 90% ICA stenosis
Confetti sign
Post-stenotic zone/ Immediately after stenosis
• Cannot be precisely quantified (evaluated visually)
Fill-in of spectral window > 50% diameter reduction
Severely disturbed flow > 70% diameter reduction
High amplitude & low frequency Doppler signal
Flow reversal
Poor definition of spectral border
• May be only sign of carotid stenosis in calcified plaque
Spectral broadening
Spectral broadening
Immediately after stenosis
High amplitude & low frequency Doppler signal
Poor definition of spectral border
Flow reversal
Severe spectral broadening: > 70% diameter reduction
Pseudo-spectral broadening
• High gain setting
• Vessel wall motion
• Tortuous vessels
• Site of branching
• Abrupt change in vessel diameter
• ↑ velocity: athlete - high cardiac output - AVF1 - AVM2
• Aneurysm, dissection, & FMD3
1AVF: Arterio-Venous Fistula
2AVM: Arterio-Venous Malformation
3FMD: Fibro-Muscular Dysplasia
Post-stenotic zone / Distal to site of stenosis
Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704.
Tardus-parvus waveform
Sonographic features of severe ICA stenosis
Significant visible plaque (≥ 70% diameter reduction)
PSV > 230 cm/sec
EDV > 100 cm/sec
ICA/CCA PSV ratio ≥ 4.0
Spectral broadening
Color aliasing despite high velocity scale (100 cm/sec)
Color bruit artifact in surrounding tissue of stenosis
High-pitched sound at pulsed Doppler
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Tight stenosis or occlusion?
• Difficult to distinguish tight stenosis from occlusion
• Completely occluded ICA
Will not release emboli
Not corrected by surgery
• Very severe stenosis
Potential source for emboli or acute thrombosis
May require urgent surgery
Optimization of low flow velocities
• Decreased color velocity scale
• Increase color, power & pulsed Doppler gain
• Decreased wall filter
• Focal zone at level of diseased segment
• Doppler angle as low as possible (60° or less)
• Increased persistence
• Increase sample volume gate
Subtotal occlusion of ICA
“string sign” or “trickle flow ”
Narrow channel of low-velocity in subtotal ICA occlusion
Low PRF & low filter required to detect low-velocity flow
High grade “string sign” stenosis
Tardus-Parvus waveform
Tardus: Long rise time
Parvus: Low PSV
Endarterctomy without arteriography
• Arteriography Expensive
Risks: stroke (0.1 – 0.6%) – death (0.1%)
Rarely affect surgical plan
Sufficient information obtained with MRI
• Conditions Good experience of US department
Stenosis localized to carotid bifurcation
Unequivocal US findings
Symptoms ipsilateral to carotid stenosis
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Causes of image/Doppler mismatch
• Cardiac arrhythmia
• Severe aortic stenosis
• Hypotension or hypertension
• Tortuous vessels
• Hypoechoic, anechoic or calcified plaques
• Long segment high grade stenosis
• Pre-occlusive lesion
• Tandem lesion
• Contro-lateral carotid stenosis
• Carotid dissection
Short & long stenosis of ICA
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Zwiebel WJ et al. Ultrasound Quarterly 2005 ; 21 : 113 – 122.
Short stenosis (frequent) Long stenosis (rare)
PSV lower than expected
EDV maintained at high level
Can produce very high PSV
(> 500 cm/s)
Long stenosis of ICA
Zwiebel WJ et al. Ultrasound Quarterly 2005 ; 21 : 113 – 122.
RICA
RICA: PSV 183 cm/sec
EDV 105 cm/sec
CCA: PSV 76 cm/sec
PSV ratio: 2.4
Inconsistent data
Long stenosis of ICA > 70%
Occlusion of ICA
• Absence of flow by color, power & pulsed Doppler
• “Internalization” of ipsilateral ECA waveform
• Reversed flow in ICA or CCA proximal to occlusion
• Thrombus or plaque completely fills lumen of ICA
• Externalization of ipsilateral CCA or proximal ICA
• Higher velocities in controlateral CCA vs ipsilateral CCA
Occlusion of ICA
“to-and-fro” flow or thud flow
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Damped systolic flow
Reversed flow in early diastole
Pulsed Doppler of CCA
Internalization of ECA
Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704.
Patient with complete occlusion of left ICA
Occlusion of CCA
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Reversed flow from ECA
to supply ICA & brain
“ECA-to-ICA collateralization”
Occlusion of CCA
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Absence of flow in distal CCA
Reversed flow in ECA
Normal flow in ICA
Internalization of ECA
Delayed systolic acceleration (tardus)
Positive temporal tap maneuver
Ectatic CCA
Ectatic CCA as it arises from inominate artery
Responsible for pulsatile right supra-clavicular mass
High-resistance flow in vertebral artery
High-resistance flow
No diastolic component
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Distal VA stenosis or occlusion
Hypoplastic vertebral artery
Differential diagnosis:
Dizziness
Unsteady walking
Correlation with symptoms
Vertebral artery occlusion
V2
Black & white US Color Doppler
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Route of flow in left vertebral steal
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Types of subclavian steal
Transient reversal of vertebral flow during systole
Converted to partial or complete by provocative maneuver
Pre-steal or bunny waveform
Striking deceleration of velocity in mid or late systole
High-grade stenosis of subclavian rather than occlusion
Incomplete steal
Complete reversal of flow within vertebral artery
Complete steal
Provocative maneuver in steal syndrome
Conversion of pre-steal waveform to more pronounced steal
following deflation of pressure cuff
* Inflation of pressure cuff greater than systolic arterial pressure on ipsilateral arm
Kliewer MA et al. Am J Roentgenol 2000 ; 174 ; 815 – 9.
Inflation of pressure cuff on arm for 3 min & rapid deflation*
Pre-steal More pronounced steal
Limitations of carotid US examination
• Short muscular neck
• High carotid bifurcation
• Tortuous vessels
• Calcified shadowing plaques
• Surgical sutures, postoperative hematoma, central line
• Inability to lie flat in respiratory or cardiac disease
• Inability to rotate head in patients with arthritis
• Uncooperative patient
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Advantages of power mode Doppler
• Angle independent
• No aliasing
• Increases accuracy of grading stenosis
• Distinguish pre-occlusive from occlusive lesions
“detect low-velocity blood flow”
• Superior depiction of plaque surface morphology
Disadvantages of power mode Doppler
• Does not provide direction of flow
New machines provide direction of flow in power mode
• Does not provide velocity flow information
• Very motion sensitive (poor temporal resolution)
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Fibromuscular dysplasia
Middle age women – Renal arteries – String of beads pattern
Alternating zones of vasoconstriction & vasodilation for 3 – 5 cm
ICA frequently – VA less frequently
Usually bilateral
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
ICA
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Carotid & vertebral dissection
• Spontaneous dissection Bleeding from vasa vasorum
Most common ICA & VA (atlas loop)
Intramural hematoma
Pain – Stenosis – Horner
• Vascular injury Iatrogenic: puncture – surgery
CCA
Intramural hematoma ± intimal tear
• Stanford A dissection Intimal rupture in ascending aorta
CCA
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Dissection of aorta & cervical arteries
Patho-anatomy
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Intimal rupture with false lumen
Open or secondarily thrombosed
Aorta
External intramural hematoma
Lumen constriction
Rare intimal rupture
Cervical
Spontaneous dissection of ICA
Asymmetric wall hematoma – Lumen stenosis – Expansion to outside
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Diagnostic criteria (one sufficient)
Intramural hematoma
Intimal rupture/double lumen
Distal stenosis or occlusion
Symptoms: acute pain, Horner,
Course: recanalization in few weeks
Spontaneous dissection of VA
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Wall hematoma in V1
Diagnostic criteria (one sufficient):
Intramural hematoma (asymmetric, not concentric)
Intimal rupture/double lumen (rare)
Double lumen in V2
Thoracic aortic dissection
Stanford classification
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Type B
Dissection of descending aortaDissection of ascending aorta
Possible continuation to supraaortic vessels
Type A
Dissection of common carotid artery
Stanford A
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Transverse view Longitudinal view
Detection of two lumina & dissection membrane
Dissection of CCA / Stenosis
Residuum after end of aortic dissection
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Doppler of true lumen
Enlargement of false lumen
before cranial end
Doppler of false lumen
Stenosis of true lumen
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Vasospasm
• Causes Migraine, eclampsia, vasculitis, drug abuse, idiopat
• Incidence Rarely identified (short duration)
Occur frequently & remain undetected
• Symptoms Cerebral or ocular ischemia
• US Direct &/or indirect signs of severe stenosis
Far above bifurcation – Sometimes bilateral
Complete regression in hours to days – Relapse
• Dd Dissection: wall hematoma – regression in weeks
• Treatment Calcium antagonists
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Vasospasm
Janzarik WG et al. Stroke 2006 ; 37 : 2170 – 2173.
Severe narrowing of ICA No stenosis detected
4 days later
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Extra-cranial ICA aneurysms
Clevert DA et al. Clin Hemorheology Microcirculation 2008 ; 39 : 133 – 146.
Color Doppler US Power Doppler US
Uncomplete delineation of aneurysm – Thrombi could not be excluded
Difficult definition for extracranial carotid artery aneurysms
due to normal dilatation of bulb
ICA aneurysm / Parietal thrombosis
Terborg C et al. Ultraschall Med 2007 ; 28 : 216 – 218.
Aneurysm of proximal ICA
Parietal thrombus & homogeneous thickening of vessel wall
Longitudinal section Transversal section
CCA aneurysm / Rupture
Clevert DA et al. Clin Hemorheology Microcirculation 2008 ; 39 : 133 – 146.
CCA pseudoaneurysm / Rare
One month after bilateral neck dissection
Flor N et al. J Laryngol Otol 2007 ; 121 : 497 – 500.
CCA Pseudoaneurysm
Large connecting neck
Color Doppler US CE multidetector CT
CCA Pseudoaneurysm
Large connecting neck
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Arterio-venous fistula
Attempt to perform US-guided jugular catheter insertion
Clevert DA et al. Ultraschall Med 2010 ; 31 : 610 – 612.
Turbulent flow in fistula track High-velocity turbulent flow in track
Suspicion of communication between CCA & IJV
CCA
IJV
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Doppler ultrasound in arteritis
“macaroni sign” & “halo sign”
• 2 types Takayasu Young female – SCA & CCA
Horton Old female – SCA, AA & Temporal A
Cannot be differentiated using US
• US signs Macaroni Concentric hypoechoic wall thickening
Halo Dark halo around colorful lumen
All grades of stenosis – Thrombotic vessel
• Dd Dissection Eccentric hypoechoic wall thickening
Pronounced outward expansion
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Takayasu’s arteritis
Young female – SCA [„pulseless‟ disease] – CCA
CCA
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Long hypoechoic wall thickening
Visualized in color Doppler as dark halo around vascular lumen
Horton's arteritis / Giant cell arteritis
Concentric hypoechoic wall thickening
Superficial temporal artery
VA – Longitudinal view VA – Transverse view
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
1 sAUROC: Summary Area Under Receiver Operating Characteristic
2 DOR: Diagnostic Odds Ratio
Ball EL et al. Br J Surg 2010 ; 97 : 1765 – 1771.
MA of US in diagnosis of temporal arteritis
Halo sign versus temporal artery biopsy
9 studies – 357 patients
Sensitivity 75% (67 – 82)
Specificity 83% (78 – 88)
sAUROC1 0.868
DOR2 17.96 (6.72 – 47.99)
Heterogeneity I2 = 27%, P < 0.204
US relatively accurate for diagnosis of temporal arteritis
US as first-line investigation, biopsy if negative scan
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Carotid body tumor / Rare
Histology Paraganglioma of low malignant potential
Presentation Palpable neck mass – Headache – Neck pain
US Highly vascular mass in carotid bifurcation
Arteriography Performed preoperatively – Embolization
Treatment Resection to prevent local adverse events:
Laryngeal nerve palsy – carcinoma invasion
Result Local recurrence 6% – Distant metastasis 2%
Carotid body tumor
Highly vascular mass in carotid bifurcation
Zwiebel WL. Introduction to vascular ultrasonography.
W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause
Diagnosis of idiopathic carotidynia
International Headache Society (IHS)1
• At least one of following over CA: Tenderness
Swelling
Increased pulsations
• Pain over affected side of neck that may project to head
• Appropriate investigations without structural abnormality
Recent publications demonstrate radiological findings2
• Self-limiting syndrome of less than 2 weeks duration
1 International Headache Society. Cephalalgia 1988 ; 8 (Suppl 7) : 1 – 96.
2 Kosaka N et al. Eur Radiol 2007 ; 17 : 2430 – 2433.
Idiopathic carotidynia
US findings comparable to dissection
Kosaka N et al. Eur Radiol 2007 ; 17 : 2430 – 2433.
Enhanced tissue
around carotid artery
CE T1-weighted MRIUS of distal CCA
Hypo-echoic soft tissue
around carotid artery
Three months later
Resolution of abnormal
soft tissue
Spontaneous dissection & carotidynia
Spontaneous dissection Carotidynia
Location Beyoud bifurcation At or near bifurcation
Thickening layers One wall layer 2 wall layers
Stenosis May be detectable Not detectable
Pain Head Neck
MRI Native enhancement Enhancement after CAs
In unclear cases, MRI enables differentiation
Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
Doppler US of carotid arteries
Anatomy of carotid arteries
Normal Doppler US of carotid arteries
Causes of carotid artery disease
Effect of extra-carotid diseases
Effect of extra-carotid diseases
• Idiopathic dilated cardiomyopathy
• Aortic regurgitation
• Aortic stenosis
• Stenosis of right innominate artery or origin of LCCA
• High & low PSV in CCA
• Stenosis of intra-cranial ICA
Idiopathic dilated cardiomyopathy
Pulsus alternans
Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704.
PSV oscillating between two levels on sequential beats
Cardiac rhythm remains regular throughout
Aortic regurgitation
Bisferious waveform [“beat twice” in Latin]
Kallman CE et al. Am J Roentgenol 1991 ; 157 : 403 – 407.
Rohren EM et al. AJR 2003 ; 181 : 169 5– 1704.
Two systolic peaks separated by midsystolic retraction
Dicrotic notch
Found also with hypertrophic obstructive cardiomyopathy
Severe aortic regurgitation
Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704.
Normal or elevated PSV followed by precipitous decline
Revered flow during diastole
Water-hammer spectral appearance
CCA
High cardiac output: Hypertensive patients
Young athletes
High flow > 125 cm/sec in both CCAs
Poor cardiac output: Cardiomyopathies
Valvular heart disease
Extensive myocardial infarction
Low flow < 45 cm/sec in both CCAs
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Arrhythmias can be real problem
Normal PSV in CCA (45 – 125 cm/sec)
ICA
High-grade stenosis distally (intracranial ICA)
Major occlusive lesions of cerebral arteries (MCA, ACA)
Massive spasm of cerebral arteries from intracranial hemorrhage
Stenosis of intra-cranial ICA
High resistance waveform
Abropoulos NL et al. Vasc Endovascular Surg 2007 ; 41 : 417 – 427.
CCA, which has no branches, divides into the internal and external carotid arteries.Carotid artery widens at the level of the bifurcation to form the carotid bulb & degree of widening of carotid bulb is quite variable.Level of the carotid bifurcation in the neck is highly variable.Proximal branches of the ECA are the superior thyroid, lingual, facial and maxillary arteries.Vertebral artery is the first branch of the subclavian artery, arising from the highest point of the subclavian arch. At the sixth cervical vertebra, the vertebral artery runs posteriorly to travel upward through the transverse foramen of cervical vertebrae.Two vertebral arteries join, at the base of the skull, to form basilar artery, which then divides to form posterior cerebral arteries.
Tortuosity can cause apparent velocity increase even although there is no stenosis. This is due to difficulty in obtaining a correct insonating angle, non-linear or helical flow, or increased velocityon the inside of the curve. Try sampling just beyond the curve.
“Saw-tooth” appearance: مظهر أسنان المنشار
Endarterectomy decrease the risk of ipsi-lateral hemispheric stroke or death by 53 to 84% as compared to medical treatment.
Cauliflower: قرنبيط
Eddy: دوامة
A panel of experts from a variety of medical specialties was convened under the auspices of the Society of Radiologists in Ultrasound to arrive at a consensus about the performance of Doppler ultrasonography (US) to aid in diagnosis of internal carotid artery (ICA)stenosis. The panel met in San Francisco, Calif, October 22–23, 2002, and drew up a consensus statement. Although there are several facets of carotid disease that could be considered by such a panel, carotid stenosis(and by extension, carotid occlusion) is by far the most common pathologic process involving carotid arteries.The panel consisted of a moderator and 16 panelists from various medical specialties.
the method used to report the degree of narrowing from an angiogram differed between the European and North American trials.In the ECST trial, the degree of stenosis was measured by comparing the residual lumen diameter with the estimated diameter of the carotid bulb, whereas the NASCET trial compared the residual lumen diameter with the diameter of the normal distal ICA.
In the North American Symptomatic Carotid Endartectomy Trial, the narrowest portion of the vascular lumen was compared with the “normalized lumen distally”.In the European Symptomatic Carotid Trial study and studies performed prior to the NASCET study, the degree of stenosis was determined by comparing the narrowest diameter of the residual lumen to an estimate of the original lumen in the same area. Because the original lumen cannot be depicted on the angiogram, exact measurement is impossible.The panel recommended that the NASCET method of carotid stenosis measurement should be employed when angiography is used to correlate the US findings. While the NASCET method of measurement may not reflect the burden of atherosclerosis in the proximal ICA, it does minimize the amount of interobserver variability.
string sign” stenosis: علامة الخيط أو الحبل أو السلك
Long stenosis: > 2 cm
It can be difficult to distinguish tight stenosis from occlusion. A completely occluded ICA cannot be corrected by surgery and will not release emboli. However, very severe stenosis can be a potential source for emboli or acute thrombosis and may require urgent surgery.
Thud: صوت مكتوم
The ECA is an important collateral pathway in patients with ipsilateral ICA occlusion and recurrent symptoms.This may influence the surgical decisions involving revascularization of the stenotic ECA.
Differentiation between these causes is important, as some centers are performing vertebral artery angioplasty and stent placement for significant vertebral artery stenosis.
Wall hematoma: Wall hematoma might be incorrectly interpreted as arteritis.However, an important differentiation criterion is the eccentric location of the wall thickening in the case of dissection as known from MRI findings, while vasculitis is characterized by concentric wall thickening.Double lumen:If double are detected, a pathological Doppler curve (showing stenosis or oscillating flow) will be found in at least one of the lumina. Therefore, fenestration of the VA (an anomaly with a double lumen in one vessel segment) cannot be confused with dissection becauseof the normal flow pulse curve in both lumina.Horner:
If 2 lumina are detected, a pathological Doppler curve (showing stenosis or oscillating flow) will be found in at least one of the lumina. Therefore, fenestration of the VA (an anomaly with a double lumen in one vessel segment) cannot be confused with dissection because of the normal flow pulse curve in both lumina.
True aneurysm generally defined as dilation of an artery to more than 150% of its normal diameterDifficult definition for extracranial carotid artery aneurysms due to normal dilatation of bulbDe Jong et al. proposed that ECAA of the bifurcation are better defined as a bulb dilatation greater than 200% of the diameter of the ICA or 150% of the diameter of the common carotid artery, and distal aneurysms of the extracranial internal carotid arteries (EICAA) as a dilatation greater than 120% of the diameter of the normal ipsilateral ICA.
Temporal (giant cell) arteritis affects the superficial temporal arteries in older women.The specificity of the method under qualified application is 97%. Therefore, given a clear vasculitis finding in the ultrasound image and an experienced examiner, a vascular biopsy can be dispensed with.In the case of unclear ultrasound findings or ultrasound findings without pathological findings and a clinical suspicion of arteritis, biopsy is still necessary.
Each diamond corresponds to a study estimate of sensitivity and specificity.Area of each diamond is proportional to the study sizeThe upper and lower curves represent the 95 per cent confidence intervals of the diagnostic odds ratio in the equation of curve.The presence of any of the markers of vascular inflammation (halo, stenosis, occlusion), compared with halo alone, seemed to improve sensitivity, while retaining specificity, although there was significant between-study heterogeneity (I2 = 81·7 per cent, P < 0·001).
“carotidynia” was initially described by Fay in 1927.Clinical criteria for dg of idiopathic carotidynia were established in 1988 by International Headache Society Classification Committee.The existence of this entity remained controversial and led the International Headache Society to remove carotidynia from their main classification of Headache Disorders in 2004.Severe pain on one side in the upper cervical region that responds well to cortisone or NSAIDs.
Pulsus alternans: نبض متناوبPatient with pulsus alternans caused by idiopathic dilated cardiomyopathy.
Pulsusbisferiens, Latin for ‘‘beat twice,’’ is the term used to describe a waveform characterized by two systolic peaks with an interposed midsystolic retraction. Visualization of this waveform suggests the presence of aortic insufficiency with or without concomitant aortic stenosis or hypertophicobstructive cardiomyopathy.Mechanism of pulsusbisferiens in aortic insufficiency is not well understood. One view is that first peak represents initial high-volume ejection of blood, which is followed by abrupt mid systolic flow deceleration caused by regurgitant valve, and second peak represents tidal wave reflected from distended aorta as it relaxes or from periphery of body.
Water Hammer: الطرق المائي (صوت طرق الماء على جوانب الأنبوب الذي يحتويه)Hammer: مطرقةSpectral waveforms mirror physical examination finding of water-hammer pulses in patients with severe aortic regurgitation.
Reduced right arm systolic blood pressure. A right-to-left difference of 20 mm Hg is considered significant.